Luteinizing follicular cyst in a dog
History: Tissue from an 11 month old female Great Dane. The tissue was removed during a routine spay surgery and submitted for histopath due to abnormal appearance.
Ovary: In each section examined there are primary follicles present in a fibrovascular stroma. There are two normal corpora lutea present consisting of a large solid mass ofpolygonal cells with large intracytoplasmic lipid vacuoles (luteinized cells). In addition there are two large cystic follicles partially lined by luteinized cells and partially lined by follicular epithelium.
Luteinized ovarian cysts are derived from anovulatory Graffian follicles and can cause hyperestrogenemia in some cases and are associated with cystic endometrial hyperplasia and development of pyometra in dogs.